The NFL playoffs have produced a number of memorable upsets over the years, from Joe Namath&#39;s New York Jets in Super Bowl III to the New York Giants spoiling New England&#39;s perfect season a few years ago. Here&#39;s a rundown of the six biggest playoff upsets in NFL football since the Super Bowl era began, counted down in reverse order. 6. Minnesota beats San Francisco, Divisional playoffs, January 1988 Even with two NFL Hall of Fame quarterbacks and the greatest receiver of all-time on their roster, the 13-2 San Francisco 49ers couldn&#39;t get past...